A Mills man has admitted that he attacked an inmate while serving time at the Natrona County Detention Center.

John Kosmata has pleaded guilty to one count of aggravated assault.

The Natrona County Sheriff's Office says in early February 2016, deputies at the Natrona County Detention Center found Michael Rollins lying in a pool of blood, with injuries that suggested he was attacked.

According to a report, one laceration was deep enough to see his skull

He was taken to the ICU at the Wyoming Medical Center and put on a ventilator.

Witnesses say Kosmata was angry about other inmates being loud after lights out.

He was arguing with another inmate, when Rollins approached them, insulted Kosmata and then a fight ensued.

After reviewing security camera footage, investigators determined that Kosmata threw the first punch.

At the time of the attack, Kosmata was serving a one year jail sentence in an unrelated case, where he pleaded guilty to two misdemeanor charges of domestic battery.

As part of a plea deal, prosecutors will seek no more than a five-to-10 year prison sentence, and will not seek habitual offender's status, which would have enhanced his sentence.

Kosmata will be sentenced at a later date.